2 * Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/eval.h"
23 #include "libavutil/imgutils.h"
24 #include "libavutil/pixdesc.h"
25 #include "libavutil/opt.h"
26 #include "libavutil/video_enc_params.h"
33 typedef struct QPContext {
41 static const char *const var_names[] = { "known", "qp", "x", "y", "w", "h", NULL };
43 #define OFFSET(x) offsetof(QPContext, x)
44 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
46 static const AVOption qp_options[] = {
47 { "qp", "set qp expression", OFFSET(qp_expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
51 AVFILTER_DEFINE_CLASS(qp);
53 static int config_input(AVFilterLink *inlink)
55 AVFilterContext *ctx = inlink->dst;
56 QPContext *s = ctx->priv;
64 ret = av_expr_parse(&e, s->qp_expr_str, var_names, NULL, NULL, NULL, NULL, 0, ctx);
68 s->h = (inlink->h + 15) >> 4;
69 s->qstride = (inlink->w + 15) >> 4;
70 for (i = -129; i < 128; i++) {
71 double var_values[] = { i != -129, i, NAN, NAN, s->qstride, s->h, 0};
72 double temp_val = av_expr_eval(e, var_values, NULL);
74 if (isnan(temp_val)) {
75 if(strchr(s->qp_expr_str, 'x') || strchr(s->qp_expr_str, 'y'))
76 s->evaluate_per_mb = 1;
79 return AVERROR(EINVAL);
83 s->lut[i + 129] = lrintf(temp_val);
90 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
92 AVFilterContext *ctx = inlink->dst;
93 AVFilterLink *outlink = ctx->outputs[0];
94 QPContext *s = ctx->priv;
98 AVFrameSideData *sd_in;
99 AVVideoEncParams *par_in = NULL;
100 int8_t in_qp_global = 0;
102 AVVideoEncParams *par_out;
104 if (!s->qp_expr_str || ctx->is_disabled)
105 return ff_filter_frame(outlink, in);
107 sd_in = av_frame_get_side_data(in, AV_FRAME_DATA_VIDEO_ENC_PARAMS);
108 if (sd_in && sd_in->size >= sizeof(AVVideoEncParams)) {
109 par_in = (AVVideoEncParams*)sd_in->data;
111 // we accept the input QP table only if it is of the MPEG2 type
112 // and contains either no blocks at all or 16x16 macroblocks
113 if (par_in->type == AV_VIDEO_ENC_PARAMS_MPEG2 &&
114 (par_in->nb_blocks == s->h * s->qstride || !par_in->nb_blocks)) {
115 in_qp_global = par_in->qp;
116 if (!par_in->nb_blocks)
122 out = av_frame_clone(in);
124 ret = AVERROR(ENOMEM);
128 par_out = av_video_enc_params_create_side_data(out, AV_VIDEO_ENC_PARAMS_MPEG2,
129 (s->evaluate_per_mb || sd_in) ?
130 s->h * s->qstride : 0);
132 ret = AVERROR(ENOMEM);
136 #define BLOCK_QP_DELTA(block_idx) \
137 (par_in ? av_video_enc_params_block(par_in, block_idx)->delta_qp : 0)
139 if (s->evaluate_per_mb) {
142 for (y = 0; y < s->h; y++)
143 for (x = 0; x < s->qstride; x++) {
144 unsigned int block_idx = y * s->qstride + x;
145 AVVideoBlockParams *b = av_video_enc_params_block(par_out, block_idx);
146 int qp = sd_in ? in_qp_global + BLOCK_QP_DELTA(block_idx) : NAN;
147 double var_values[] = { !!sd_in, qp, x, y, s->qstride, s->h, 0};
150 ret = av_expr_parse_and_eval(&temp_val, s->qp_expr_str,
151 var_names, var_values,
152 NULL, NULL, NULL, NULL, 0, 0, ctx);
155 b->delta_qp = lrintf(temp_val);
160 for (y = 0; y < s->h; y++)
161 for (x = 0; x < s->qstride; x++) {
162 unsigned int block_idx = y * s->qstride + x;
163 AVVideoBlockParams *b = av_video_enc_params_block(par_out, block_idx);
164 b->delta_qp = s->lut[129 + (int8_t)(in_qp_global + BLOCK_QP_DELTA(block_idx))];
167 par_out->qp = s->lut[0];
170 ret = ff_filter_frame(outlink, out);
178 static const AVFilterPad qp_inputs[] = {
181 .type = AVMEDIA_TYPE_VIDEO,
182 .filter_frame = filter_frame,
183 .config_props = config_input,
188 static const AVFilterPad qp_outputs[] = {
191 .type = AVMEDIA_TYPE_VIDEO,
196 const AVFilter ff_vf_qp = {
198 .description = NULL_IF_CONFIG_SMALL("Change video quantization parameters."),
199 .priv_size = sizeof(QPContext),
201 .outputs = qp_outputs,
202 .priv_class = &qp_class,
203 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,